String formatTimestamp(int? timestamp) {
  if (timestamp == null || timestamp == 0) {
    return "暂无记录";
  }
  DateTime dateTime = DateTime.fromMillisecondsSinceEpoch(timestamp);
  String formattedDate =
      "${dateTime.year}/${dateTime.month.toString().padLeft(2, '0')}/${dateTime.day.toString().padLeft(2, '0')}";
  String formattedTime =
      "${dateTime.hour.toString().padLeft(2, '0')}:${dateTime.minute.toString().padLeft(2, '0')}";
  return "$formattedDate $formattedTime";
}
